Hypersensitive reactions to mosquito bites in congenital agammaglobulinemia

A 6-year-old girl with congenital agammaglobulinemia exhibited severe delayed onset cutaneous reactions to mosquito bites with scar formation. The bites were not associated with immediate reactions accompanied by itching. The patient had non-detectable IgE levels (less than 0.2 IU/mL) in addition to absence of three other major classes of immunoglobulins, but showed normal T cell functions. Immunologic and histopathologic examination of the skin lesions revealed that this unusual reaction may be caused by a delayed type hypersensitivity response.